Women often wear shoes with different heel heights. For example, when commuting, a woman may prefer to wear a low heeled shoes, flat shoes or sneakers. Wearing such shoes is more comfortable than wearing high heeled shoes when having to walk or drive a distance. Then, upon arriving at her place of business, she may prefer to wear a shoe with a higher heel. This may pose a problem or, at the very least, an inconvenience as the woman would have to carry an extra pair of shoes to work and then change once she has arrived. Alternatively, she may have to leave several pairs of shoes at the workplace. This creates a further problem if the woman finds that she needs a pair of shoes that have been left at the workplace, such as during the weekend.
In another situation, a woman may find that she needs shoes with differing heel heights when traveling. This creates a problem when packing a suitcase in that many pairs of shoes need to be stored within a confined space. Shoes are rather bulky and awkward to pack and often take up a lot of space within a bag.
Also, extended use of high heeled shoes may cause foot ailments. The present invention serves to decrease the incidence of those ailments by offering women the opportunity to reduce the total time that they wear shoes that have high heels.
Solutions to the situations discussed above have been proposed. See, for example, U.S. Pat. No. 2,258,265 to Schwartz and U.S. Pat. Nos. 3,464,126 and 4,416,072 to Sarkissian. The Schwartz solution is unacceptable as it requires a women to carry multiple heels with her and to attach the one that is desired each time she wishes to change the height of her heel. Sarkissian, on the other hand does not actually change the height of the heel but simply moves the inner sole of the shoe up or down relative to the fixed heel. This results in a rather complex arrangement.
Prior U.S. Pat. No. 5,309,651 to Handel (one of the present Applicants) was an improvement on the several patents discussed above in that it provided for a two part heel wherein the lower heel part could be moved between an upright position to form a high heeled shoe to a stowed position to form a low heel shoe. In the stowed position, the lower heel part is positioned out of the way beneath the arch portion of the shoe.
It was subsequently found, however, that the mechanism that permitted such movement is not sufficiently stable or strong enough to prevent disengagement of the two heel parts with resultant collapse of the heel. This design flaw in that invention is due to a couple of factors. First, when in the high heel position, the wearer's weight is born almost entirely by the impaction of the high and low heel parts against each other and against the intervening low heel lift. As that lift wears away from use, the weight bearing interface between the parts becomes diminished. Furthermore, the high and low heel parts when in the high heel position are guided and biased together by a spring biased pin or post. This spring/pin combination is inherently unstable because the pin, surrounded by a spring, can not be fitted within a channel with a tight enough tolerance to prevent wiggle and movement since an allowance must be made for the fact that the spring diameter changes between the states when it being compressed or distracted. The result is that the mechanism is unstable and can easily allow the heel parts to wiggle and topple. This is particularly true as the low heel lift mentioned above wears away.
Therefore, a need exists for a shoe with an adjustable heel height that is easy and convenient for a woman to utilize but which is strong and stable enough to provide adequate support for the wearer.